Phal w/o aerial roots and not producing new leaves

[onmi]

Hi all,

I'm not sure whether I should consider myself a beginner, but here is a question: I have 2 orchids that I repotted several years ago. They both grow in the same conditions - light, watering, soil, etc. Since I repotted they both have been blooming non-stop. I literally can not repot them as the new branches with blossoms are coming out before the old ones die off. However, one of the orchids produces lots of new aerial roots and new leaves (occasionally) as well. While the other one has not had a new leaf or aerial root since the repotting. But it blooms the same way as the first one. Also, an interesting moment is that the spot where new leaves should be coming from is kind of hard, like there was some old stem (or something like that) and it was cut and became dry and hard. Maybe you can see it in the pictures. The white one has no problems while the purple is the one I'm concerned about. Or maybe there is nothing wrong with that?

1. the first picture is is the purple Phal, you can see the spot between the leaves
2. both phals. you can see how many aerial roots has the white one. also, it has more leaves.
3. here you can see both phals from above, the one with lost of aerial roots is white